Last week my transmission overheated after I saw the the gauge headed toward the red area I shut it down. After shutting it down, 2 minutes later the "Wrench" warning light came on. I hit "OK" and within 7 minutes the temp. was back in the middle.

This was the situation, My truck is a 2013 F350 4X4 SRW Crew Cab 65,000 miles towing a 15000 lbs. gooseneck trailer on a uphill service road, similar to a fire road. Was into it a mile and half into when a steeper section can and I dropped into "2" still in 2WD. Trans Temp. climbed with minutes and I shut it down. Did not look at exact temps when it happened, remember engine temp gauge in the middle. Backed the truck down the hill a short distance and unhooked. Trans gauge went down to middle (normal) and was able to continue up the hill 2 more miles no problem, without the trailer. I have towed since around town with same trailer and no problems. Checked the trans fluid and it looks like new, clear red.

Here's sum history, I'm running Mag-Hy Tech Trans pan installed at 45,000 miles with a fluid change at the time of install. Towed plenty of times in between install and date of problem.

Had the truck in for service the previous day before the overheating for Oil Change, brakes, and coolant change. Nothing related to trans.

Wondering if I have a trans cooler issue? Temp Sensor issue? OR this is the way the transmission operates and it just could take the load and conditions???

 

That was the wrong thing to do. Shutting the engine off with an overheated trans can damage the trans from heat soak. You should have let the engine idle in park or neutral to keep the fluid circulating to cool the trans.

That was another error. You'd have FAR less load on the trans in 4WD low. Also, when you dropped it into "2" what gear was the trans already operating in? If it was in first gear, dropping it into "2" would cause an upshift, adding to the load on the trans.

That does nothing for the trans except make the underside of the truck look nice.

I think it's operator error. Dropping the trans into "2" didn't help, and towing up a steep hill in 2WD sure didn't help.

 

Hi Chris, welcome to FTE!

Your truck has an oil-to-air transmission cooler, which relies on airflow through the cooler to keep your transmission cool. Going slow under load up a hill makes it really hard for this part to do it's job, so it makes sense to me why you overheated.

If this happens again, put the truck in park or neutral and let the temperature come down as the fluid circulates. Hope you didn't hurt anything!

 

Mark, I see your points and for the most part agree with you.

I have no idea why the OP selected "2"...I'd think leaving it in "D" should work. Not trying to be a smart butt here, but if my truck couldn't pull its rated load up any hill and at any speed (up to the speed limit) without over heating the engine, tranny, etc then I'd get it fixed or get rid of it. I understand 4wd low would be easier on the tranny, but if it can't pull its rated load in 2wd then something needs fixed.

 

I would agree with you unless the incline was too steep. He mentioned it was a service road which most likely is not governed like highways. In that case you need to take special precautions. Had he put the truck in 4 low it would have taken strain off the transmission.

 

It may have wanted to be in first gear until he moved the shifter to 2. That alone could make it overheat.

 

Thanks, Mark. That's good to know. I've never felt the need to shift into 2...not even sure why it's there for modern automatics with "Tow/haul" mode.

 

Forcing second gear can be useful when starting out on ice. Less torque multiplication than you'd get starting out in first gear. I believe it says this in your owner's guide.